1. Field of the Invention
The present invention relates to an evaluation system for a fault diagnosis function for a vehicle, a computer program product, and computer readable storage medium.
2. Description of Related Art
A vehicle has a various kinds of equipments, such as sensors. The vehicle also has a fault diagnosis apparatus to automatically detect a status of the sensors. The status of the sensors includes a normal operating condition and an abnormal operating condition. The fault diagnosis apparatus has a main part in which a microcomputer is included.
Under normal conditions of the fault diagnosis apparatus, the fault diagnosis apparatus can detect the status of the sensors. However, if the fault diagnosis apparatus fails to operate as intended due to some reasons, the fault diagnosis apparatus cannot detect the status of the sensors. A regulation for the fault diagnosis apparatus is suggested by California Air Resources Board (CARB) in order to check a function of the fault diagnosis apparatus. The CARB published the regulation for onboard diagnostic systems (OBD II systems) that is “OBD II Malfunction and Diagnostic system  Requirements” dated Apr. 24, 2002.
In the regulation, the function of the fault diagnosis apparatus is evaluated in an onboard condition. The regulation prescribes that an indicator lamp should illuminate a check result of the fault diagnosis. The regulation also defines a driving cycle. The driving cycle is a time period from a startup of an engine to a next startup of the engine.
FIG. 21 shows an example of an evaluation process. When the driving cycle ends, the evaluation process starts. In step 2000, it is determined whether a failure detection of the sensors by the fault diagnosis apparatus is completed or not. When the failure detection is completed, the diagnosis function is determined to be in a normal condition in step 2100.
However, in such a regulation, as shown in FIG. 22, when the failure detection is once completed, a flag “1” is stored in a memory. The flag “1” indicates a completion of the failure detection. While the flag “1” is stored in the memory, the diagnosis function is continuously determined to be in the normal condition. It is continued before the flag “1” is deleted, that is, a flag “0” is stored. The flag “0” indicates an incompletion of the failure detection.
The flag “1” can be deleted through the use of an external device. However, after that the failure detection is once completed, the flag “1” is stored in the memory. The diagnosis function is determined to be in the normal condition. The diagnosis function is again continuously determined to be in the normal condition. In such a situation, even if it is continue to be in a condition that the failure detection cannot be completed due to some reasons, the diagnosis function is determined to be in the normal condition.